package 开始的算法算法入门8月.链表;
// https://leetcode-cn.com/problems/merge-two-sorted-lists/
public class 合并两个有序链表210821 {

     public class ListNode {
         int val;
         ListNode next;
         ListNode() {}
         ListNode(int val) { this.val = val; }
         ListNode(int val, ListNode next) { this.val = val; this.next = next; }
     }

    class Solution {
        public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
            if (l1 == null) {
                return l2;
            } else if (l2 == null) {
                return l1;
            } else if (l1.val < l2.val) {
                l1.next = mergeTwoLists(l1.next, l2);
                return l1;
            } else {
                l2.next = mergeTwoLists(l1, l2.next);
                return l2;
            }

        }
    }
}
